Sikorsky Helicopters has pledged $250,000 for the first "controlled flight of a human-powered helicopter," subject to some specific requirements. University of Maryland's Alfred Gessow Rotorcraft Center students have constructed a large-scale four-rotor prototype for a vehicle which may eventually achieve that goal. The helicopter is powered by a single person pedaling with hands and feet, but still requires "spotters" to keep it under control for the duration of the 40 second flight.